Safely ignore modules named cz_ that are not plugins

commitizen/cz/__init__.py

@@ -1,21 +1,39 @@
 import importlib
 import pkgutil
-from typing import Dict, Type
+import warnings
+from typing import Dict, Iterable, Type
 
 from commitizen.cz.base import BaseCommitizen
 from commitizen.cz.conventional_commits import ConventionalCommitsCz
 from commitizen.cz.customize import CustomizeCommitsCz
 from commitizen.cz.jira import JiraSmartCz
 
+
+def discover_plugins(path: Iterable[str] = None) -> Dict[str, Type[BaseCommitizen]]:
+    """Discover commitizen plugins on the path
+
+    Args:
+        path (Path, optional): If provided, 'path' should be either None or a list of paths to look for
+    modules in. If path is None, all top-level modules on sys.path.. Defaults to None.
+
+    Returns:
+        Dict[str, Type[BaseCommitizen]]: Registry with found plugins
+    """
+    plugins = {}
+    for finder, name, ispkg in pkgutil.iter_modules(path):
+        try:
+            if name.startswith("cz_"):
+                plugins[name] = importlib.import_module(name).discover_this  # type: ignore
+        except AttributeError as e:
+            warnings.warn(UserWarning(e.args[0]))
+            continue
+    return plugins
+
+
 registry: Dict[str, Type[BaseCommitizen]] = {
     "cz_conventional_commits": ConventionalCommitsCz,
     "cz_jira": JiraSmartCz,
     "cz_customize": CustomizeCommitsCz,
 }
-plugins = {
-    name: importlib.import_module(name).discover_this  # type: ignore
-    for finder, name, ispkg in pkgutil.iter_modules()
-    if name.startswith("cz_")
-}
 
-registry.update(plugins)
+registry.update(discover_plugins())

tests/test_factory.py

@@ -1,7 +1,10 @@
+import sys
+
 import pytest
 
 from commitizen import BaseCommitizen, defaults, factory
 from commitizen.config import BaseConfig
+from commitizen.cz import discover_plugins
 from commitizen.exceptions import NoCommitizenFoundException
 
 
@@ -19,3 +22,27 @@ def test_factory_fails():
         factory.commiter_factory(config)
 
     assert "The committer has not been found in the system." in str(excinfo)
+
+
+@pytest.mark.parametrize(
+    "module_content, plugin_name, expected_plugins",
+    [
+        ("", "cz_no_plugin", {}),
+    ],
+)
+def test_discover_plugins(module_content, plugin_name, expected_plugins, tmp_path):
+    no_plugin_folder = tmp_path / plugin_name
+    no_plugin_folder.mkdir()
+    init_file = no_plugin_folder / "__init__.py"
+    init_file.write_text(module_content)
+
+    sys.path.append(tmp_path.as_posix())
+    with pytest.warns(UserWarning) as record:
+        discovered_plugins = discover_plugins([tmp_path.as_posix()])
+    sys.path.pop()
+
+    assert (
+        record[0].message.args[0]
+        == f"module '{plugin_name}' has no attribute 'discover_this'"
+    )
+    assert expected_plugins == discovered_plugins